Surge Protection Device for Led Street Lightings
THE NEED FOR PROTECTION
Why is protection needed?
LED technology has become the reference technology for lighting, mainly because of four characteristics: efficiency, versatility, energy savings and longer life.
In spite of these benefits, the technology has a number of drawbacks: Higher cost of implementation (initial investment) and internal electronics (LED optics and drivers), much more complex and sensitive to overvoltages than in the case of traditional light sources.
For these reasons, the use of overvoltage protection systems is a very cost-effective investment, since it extends the life of the luminaires, ensures the cost effectiveness (ROI) of LED projects and reduces the costs of maintenance and replacement of luminaires.
A surge protection device (SPD) connected upstream of the driver, complements the intrinsic immunity of the luminaire, creating much more robust protection against the effects of lightning and overvoltages.
Luminaires with LED technology are used in a large number of applications where overall exposure to atmospheric phenomena is generally high: street lighting, tunnels, public lighting, stadiums, industries, etc.
Overvoltages can be subdivided into 5 different types
1. Increased earth potential due to a nearby strike, depending on the resistivity of physical earth.
2. Switching due to normal operation. (e.g. all the luminaires being switched on at once).
3. Induced in the circuitry: resulting from the electromagnetic field of a nearby (<500 m) strike.
4. Direct strike on a luminaire or supply lines.
5. Permanent or temporary overvoltages (POP) due to supply problems
The likelihood of a voltage surge caused by a lightning strike or induction is usually very high in lighting installations, although the risk is determined by the nature of the installation (indoors, outdoors) and the degree of exposure (elevated locations, isolated sites, cable extensions, etc.).
Damage and cost of repairs
Drivers usually have a certain level of immunity (2 to 4 kV) to transient overvoltages. This is enough to pass the tests for luminaires but insufficient to withstand voltage surges caused by lightning (10 kV/10 kA) under field conditions.
The experience of the installed base of the LED lighting industry has shown that without a proper SPD, a high percentage of luminaires reach end of life prematurely. This leads to a number of costs for the replacement of equipment, maintenance costs, continuity of service, etc which end up adversely affecting project ROIs and their image.
Continuity of service is vital in lighting installations where good illumination is a key safety issue (crime, road safety, workplace lighting, etc.).
Proper sizing of an “SPD + luminaire” system ensures that repeated overvoltage events do not lead to driver end-of-life, or not before the SPD in the worst case. This translates into cost savings, especially because of the reduction of corrective maintenance actions.
Surge protection devices (SPD) protect equipment by discharging the overvoltage to earth, thus limiting the voltage reaching the equipment (residual voltage).
An effective overvoltage protection design comprises staggered protection, with stages for each of the sensitive components in the system. In this way part of the overvoltage is discharged in each protection stage until only a small residual voltage is left close to the luminaire.
Protection in the lighting panel “1” although necessary, is by itself insufficient because overvoltages can also be induced in long cable runs, which means that the final protection should always be as close as possible to the equipment being protected “2” “3”.
KEY DESIGN PRINCIPLES FOR THE BEST PROTECTION
Location of protection
The typical configuration of an outdoor lighting installation consists of a general lighting panel and a set of luminaires with long cable runs between them, and between them and the panel.
For effective protection in a system like this, it is essential to have staggered protection with high discharge capacity and low residual voltage. This requires a minimum of two stages of protection (see table).
Protection – in series or parallel
Surge protection devices (SPD) can be connected in series or parallel as shown in the image. Each has its advantages and disadvantages
- Parallel: if the SPD reaches end-of-life the luminaire will remain connected, giving priority to continuity of service.
- Series: if the SPD reaches end-of-life the luminaire will be turned off, giving priority to protection. This connection is recommended because it makes it possible to know if any SPD has reached its end-of-life. This avoids having to open each luminaire to check the status of the arrester.
Safety and universality
Safety and universality are key issues in both the design and the installation of the luminaire, since this provides comfort and peace-of-mind to the installer or specifier/client. Since the manufacturer often does not know where or how the luminaire is installed, only a UNIVERSAL, SAFE SPD provides a guarantee of proper operation in all cases.
How is the luminaire installed?
- The standard (IEC 60598), requires that at no time in its life should an SPD generate leakage currents. To achieve this, a component called a gas discharge tube (GDT) is used, which is not suitable on its own for the Line- PE connection. Since the L-PE connection is crucial to the safety and universality of SPDs, the solution is to use a symmetrical protection circuit so that in common mode the SPD will always have a varistor (MOV) in series with GDT to PE.
- Wiring errors. Inverting L and N is a typical error that can cause an electrical hazard in the event of surge but which is not detected during installation.
- SPD wiring in series or parallel. A compromise between continuity of service and protection for the luminaire. It’s for the final customer to decide.
Where is the luminaire installed?
- IT, TT, TN networks. A standard SPD cannot withstand a line-to-earth fault in 120/230 V networks.
- 230 V L-N or L-L networks. These networks are common in several regions and situations, not all SPDs can be connected L-L.
Temporary or permanent overvoltages (POP) are increases in voltage of more than 20% of nominal voltage up to 400 V for several seconds, minutes or hours. These overvoltages are usually due to breakage of the neutral or to unbalanced loads. The only way to protect against such events is to disconnect the load, in this case through the contactor.
Temporary overvoltage protection – POP, adds value to the installation:
- Automatic reconnection via the contactor in the lighting panel.
- Tripping curve in accordance with EN 50550.
This universal solution supports all network configurations (TN, IT, TT) and luminaire insulation classes (I & II). This range includes a series of connectors, flexible fixing and optional IP66 rating.
CB Scheme certification (issued by TUV Rheinland) and TUV mark where all points of IEC 61643-11 and EN 61643-11 have been tested.
SLP20GI guarantees the universality and safety of the luminaire:
- For all network configurations (TT, TN & IT) configurations.
- Wiring safety LN/NL reversible.
- Universality L-N 230 V, L-L 230 V
- Series/parallel wiring.
Double end-of-life indication
Disconnection If installed in series, the SPD will turn the luminaire off when it comes to its end-of-life.
Visual LED indication.
No leakage current
All SLP20GI with common mode protection have no leakage current to earth, thereby preventing any possibility of the SPD generating dangerous contact voltages.
A wide range of lighting applications, which by their nature and usage, make overvoltage protection particularly necessary. Good protection guarantees system operation (continuity of service), provides safety and helps protect the investment (ROI) in LED lighting equipment.
WHY CHOOSE LSP?
LSP, a specialist lightning and surge protection company, provides the market with a specific range for the protection of LED installations, the result of over 10 years of experience in the industry.
Your protection partner
We aim to be your partner in overvoltage protection, providing a complete solution in this field: a wide product range, technical advice.
Lightning and Surge Protection for LED Lighting / LED street lamp
The best protection solutions for LED lighting by the surge protection specialist
LSP, specialists in lightning and overvoltage protection
LSP is a pioneer in the design and manufacture of lightning and surge protection devices. For over 10 years LSP has been providing high quality solutions and products using the latest most innovative technology.
LSP offers a wide range of solutions for all types of outdoor lighting equipment and installations, inside the pole or inside the panel.
LED technology embraces the concept of efficiency, combining considerable energy saving and much greater life expectancy than traditional lighting sources. This technology, however, has a number of drawbacks:
– Its implementation requires a major investment, which in the case of destruction of the equipment would have to be repeated.
– Extreme sensitivity to overvoltages, whether caused by lightning or by switching on the grid. The very nature of public lighting installations, with its long cable runs, increased their exposure to overvoltage effects induced by lightning.
For these reasons, the use of protective systems against surges is a very profitable investment, both in terms of the lifetime of the luminaire and in savings in replacement costs and maintenance.
OEM Solutions (manufacturer)
Extend the life of your LED luminaires and avoid potential claims and damage to your image
Surge protection adds value to the manufacturer of LED lighting, providing an extra guarantee to the end user in terms of reliability and durability.
LSP, a company specialising in surge protection, provides the manufacturer with a complete solution in this field: a wide range of surge protector devices, technical advice, built-to-order products, testing of luminaires, etc.
The some manufacturers of outdoor LED luminaires are already protected by LSP
The SLP20GI range, Compact and easy to install in any luminaire
LSP has designed a compact solution which fits any luminaire. Surge protection for LED luminaires IS VERY SIMPLE TO INSTALL. Cables, terminals, etc.. … can be tailored for each manufacturer.
Solutions for all types of electrical grids
The range of surge protectors for LED luminaires is suitable for all network configurations and all voltages (including IT systems). LSP has solutions for class I and class II luminaires.
Recent studies suggest that over 80% of existing public lighting panels include no surge protection. For the remaining 20%, the protection in the panel is insufficient to effectively protect the luminaire assembly connected to the panel, because surges can also be induced along the long cable runs.
The optimal and most effective system of protection is the staggered or cascade type. First, an initial protection stage should be installed in the lighting panel (with the installation of a sturdy protector with a high discharge capacity of 40 kA, and protection against power frequency overvoltages TOV temporary overvoltages) and a second stage as close as possible to the luminaire (fine protection to complement the first stage).
It is estimated that there is an installed base of over 500,000 insufficiently protected outdoor LED lights in Europe.
Upgrading the installed base of LED luminaires with surge protection is a very profitable investment, both in terms of reduced maintenance costs, and of the protection of expensive investments.
LSP offers a wide range of solutions for efficient protection of outdoor LED lighting installations.
- reduces maintenance cost
- ensures continuity of service
- extends the life of the lights
- ensures ROI on LED technology
For the protection of sensitive electronic drivers and LED lights inside street lamps, LSP has now developed a tailor-made surge arrestor.
Energy saving LED lights used as street lighting are becoming increasingly popular. But their free-standing poles are at risk in two ways: From lightning and from surge voltages via the power supply. For the protection of sensitive electronic drivers and LED lights inside street lamps, LSP has now developed a tailor-made surge arrestor. The type 2+3 arrestor SLP20GI has a high level of conducting capacity of up to 20 kA. Having a very low protection level (UP), it is also suitable for the protection of very sensitive electronic components. Thanks to its compact design, the housing can be mounted in the pole end area or in the street lamp head. The arrestors SLP20GI fulfil the requirements for T2+T3 surge protective devices according to the current EN 61643-11:2012 product norm.
Surge Protection In LED Lights
Outdoor lights are susceptible to transient spikes by lightning strikes that are inductively coupled onto power lines. Surges can be caused by direct lightning, indirect lightning or switching OFF/ON of mains supply.
Besides surges, if HV line touches LV line or if neutral connection is weak or floating the phase- Neutral voltages can go higher than prescribed limits of luminaire. For the purpose of this article we will focus on surge protection.
These surge voltage transients can destroy LED power supplies as well as the LED’s themselves. Due to the sensitive nature of LED lights, we need to provide over voltage, over current, surge protection for LED lighting systems ,The most common type of surge protector contains a component called a metal oxide varistor or MOV, which diverts the extra voltage & energy away from the device it is protecting. In case of LED Lights, it will protect LED Driver or LED itself.
LSP provides SPD modules which shall give protection in excess of 10kV-20kV. This protection is there between Phase-Neutral, Neutral-Earth & Phase-Earth. We offer these modules inbuilt inside the outdoor luminaires such as street lights, flood lights etc.
Surge Protection for LED Street Lights
New LED Street Lights are being installed in street and highways and replacement of conventional luminaries is also in progress because LEDs consumes less power and offer a good lifespan. Outdoor public installations are more exposed to the environment and are located where continuous service is essential. Although there are many advantages of LED lights but one major drawback of LEDs is that their repairing and replacement cost of components is relatively higher than that of conventional luminaries and LEDs gets easily affected by surges. To avoid unnecessary maintenance and long life, you must install Surge Protection for LED Street Lights.
Led street lights are affected by surges due to below major causes:
- Lightning strike, direct lightning strike to LED street light. Very long distance outdoor power distribution lines are susceptible to lightning strikes and a large current can be conducted through power lines due to lightning, cause damage to street lights.
- Indirect lightning strike causes interference in the supply line.
- High voltage surges from a power line, from switching operations, earth problems etc.
Voltage Surge is a very High Voltage Spike mainly of several Kilo-Volts, for a very small interval of time, a few microseconds. That’s why you need Surge Protection for LED Street Lights.
Many LED lighting manufacturers and suppliers notice that once LED street lights are struck by a surge, different components i.e. power supply, LED chips even sometimes full module got damage and must be replaced and the process of uninstalling the luminaire from the pole is a very difficult procedure. Although experts in lighting industry research a lot for this problem and developed some drivers with higher dielectric strength; but these drivers are very expensive and there is still a fair chance of damage in case of a surge. Again this explains the importance of surge protection for led street lights.
Investing a small amount in protection can extend the lifetime of Street Lights and reduce the overall cost of operations and infrastructure
Now the question arises is, how can we provide Surge Protection for LED Street Lights? This can be done by installing protective devices called surge arrestors on the main line and connecting it in series or parallel configuration. When connected in parallel, LED light will still work if the surge protection device is damaged because of the parallel connection.
Surge protection device (SPD) will act as a voltage controlled switch which will remain passive till system voltage is lower than its activation voltage. When the system (input voltage in case of LED street lights) increases SPDs activation voltage, SPD will divert the surge energy protecting the luminaire. Lightning is very important when installing SPDs, choose a device which can withstand maximum impulse voltage.
Installation of surge protection for led street lights:
Below figure show places where surge protection devices can be installed on the LED street light:
- Directly into the street light, installed inside driver cabinet.
- Installed inside the distribution board.
The distance between the luminaire and surge protection device must be kept minimum to ensure proper protection, it should be kept as short as possible. If the distance between the light and distribution board is more than 20 meters, use of secondary protection device is recommended in the majority of cases.
IEC Standards for Surge Protection: According to IEC61547, all outdoor lighting products must be protected from surges up to 2kV in common mode. But surge protection up to 4kV is recommended. Out of the causes mentioned in International Protection standards, the cause which affects most outdoor street lights is a direct lightning strike on distribution lines (surge conducted through power lines). Installation area must be properly checked and accessed for the possibility of lightning strikes and the chances of a lightning strike are higher, protection of 10kV is recommended.
Protection of LED lights against overvoltage
Overvoltage causes, experiences and protection concepts
The trend towards LED lighting in interior and exterior lighting is steadily increasing. In the meantime, many local authorities and network operators throughout Europe have experience with this relatively new technology. It seems that the advantages, especially in terms of energy savings and intelligent lighting control, will ensure that the share of LED solutions in lighting technology will continue to rise steadily in the future. In street lighting, this is already evident in many cities, but the trend is also on the rise in industrial and building lighting. However, here too it is clear that there are both light and shade sides.
In recent years, it has become apparent that over-voltages in particular represent a serious problem for sensitive electronics. Initial feedback from the field confirms this. The city of Esbjerg, for example, reported the largest failure to date of over 400 street lights as a result of a lightning strike. This is particularly worth mentioning as Denmark is one of the lightning poorest regions in Europe.
Lightning strikes can reach very high values depending on the distance of the impact location, the ground and earthing conditions and the flash intensity. Fig. 1 shows the qualitative influence on the light points of street lighting caused by the formation of a potential funnel at a lightning strike.
During switching operations in the network, voltage peaks of several thousand volts are generated, which propagate in the low-voltage network and load other equipment.
A typical example is the tripping of fuses or mixed networks with LED and conventional discharge lamps with conventional ballasts, which provide several thousand volts of ignition voltage.
Electrostatic charges are a phenomenon which occurs particularly in the case of Protection class II Luminaires where charge separation occurs and then a high voltage on the luminaire housing or heat sink of the LED. This phenomenon is a real challenge for every car driver. who, when he grips his car, can sometimes get an electric shock got.
Particularly affected are luminaires which are operated completely isolated from earth potential.
Mains faults can lead to so-called temporary overvoltages. The drop in the neutral conductor, e.g. due to damage, is the most frequent cause here. With this fault, the nominal voltage can increase up to 400 V on the phases due to mains asymmetries in the 3-phase mains. The protection against temporary overvoltages requires special consideration.
But there are also problems in building and hall lighting. In particular where overvoltages do not originate from outside, but daily from the own plant. In particular, cases are known from the industry, in which which generate overvoltages in electrical equipment and which are caused by the electrical wiring reaches the lighting. First sporadic failures individual luminaires or LEDs are the typical signs of this.
Based on this experience, too, luminaire manufacturers have met their requirements for to the strength of the luminaires against overvoltages. Lag the strength of street luminaires against overvoltages several years ago. at approx. 2,000 – 4,000 V, it currently averages approx. 4,000 – 6,000 V.
This experience has also prompted luminaire manufacturers to raise their requirements for luminaire strength against surge voltages. Whereas a few years ago the strength of street luminaires against overvoltages was approx. 2,000 – 4,000 V, it is currently approx. 4,000 – 6,000 V on average.
In order to take this into account, many luminaire manufacturers offer the option of Luminaires with a powerful Type 2+3 surge protection device (SPD) to protect the world. If this is not possible or intentional, e.g. due to lack of space or because the luminaires are already installed in the field, the SPD can also be installed in the mast fuse box. can be used. This also offers the advantage of the simpler Maintenance and retrofitting. To complete the protection concept and relieve the light points. It should additionally be equipped with a combined arrester type 1+2 in the street switchgear/Central distributor against the propagation of lightning currents and overvoltages be protected.
In building services engineering, effective protection can be achieved by equipping the electrical installation with lightning and surge protection devices. For example, combined lightning and surge arresters type 1+2 can be used for protection against lightning currents and mains transients in building feed-in systems, and SPD type 2+3 light distribution boxes and junction boxes for luminaires can be used for protection against field couplings and switching overvoltages.
Practical overvoltage protection
There are many manufacturers for surge protection on the market. Therefore should be based on the following points when selecting surge protection devices be paid special attention to.
A good overvoltage protection should be tested according to IEC 61643-11 and the requirements of VDE 0100-534. In order to achieve this, the following requirements are among others met status signalling and disconnecting devices are integrated in the SPD.
Since the SPD is usually concealed at inaccessible points, e.g. in luminaires is installed, pure optical signalling is not ideal. An SPD that can also disconnect the luminaire from the circuit in the event of a fault, the following features are available here a good and simple way of indirect signalling.
LED technology is becoming increasingly important in lighting. Further development technology ensures ever more reliable solutions. Practice-oriented, adapted Overvoltage arresters and protection concepts fuse the sensitive electronics from harmful overvoltages. The additional costs of an effective overvoltage protection concept for a luminaire system currently account for less than one percent of total costs. Overvoltage protection measures are therefore a must for every plant operator. simple and in many cases indispensable means of ensuring the long service life of the and reliability of the lighting and to avoid consequential costs.
Surge protection concepts for LED street lighting systems
Long-lasting LED technology means less maintenance jobs and lower costs
Street lights are currently being retrofitted by many communities and municipal utilities. Conventional luminaires are primarily replaced with LEDs. Why is this conversion taking place now? There are many reasons: funding programmes, energy efficiency, bans on certain lighting technologies and, of course, lower maintenance for LED luminaires.
Better protection for expensive technology
LED technology has many advantages. However, it also has a lower surge immunity than conventional luminaire technologies. What is more, the LED luminaires are more expensive to replace. In practice, damage analyses have revealed that surges usually damage more than one LED street light at a time.
- Prevent failure
- Include Surge Protection
Typical damage resulting from surges may be the partial or complete failure of the LED module, destruction of the LED driver, loss of brightness or failure of the entire control electronics.
Even if the LED luminaire continues to function, surges usually have a negative influence on its service life.
Avoid unnecessary maintenance jobs and safeguard availability with an effective bespoke surge protection concept.
SLP20GI is the ideal arrester for you – you can install the IP65 version outside it.
Simply get in touch with us. We will be pleased to assist you with your planning.
Surge protection for indoor LED lighting
Powerful surge arresters protect sensitive LED technology. They prevent damage and ensure the longevity of the LED light.
As an operator, you reduce replacement costs and save on expensive and time-consuming maintenance work.
A further advantage: permanent availability of the lighting means undisturbed working and production processes as well as satisfied users.
Protection concept indoor LED lighting
For a comprehensive protection concept, consider the following installation locations:
A – directly on the LED lighting / on the light strip
B – in the upstream sub-distribution system
This table shows the recommended C136.2-2015 transient immunity levels for common outdoor lighting applications:
Table 4 – 1.2/50µs – 8/20µs Combination wave test specification
|1.2/50µs open-circuit voltage peak Uoc||Typical: 6 kV||Enhanced: 10kV||Extreme: 20kV|
|8/20µs short-circuit current peak In||Typical: 3 kA||Enhanced: 5kA||Extreme: 10kA|
|Coupling modes||L1 to PE, L2 to PE, L1 to L2, L1+L2 to PE|
|Polarity and phase angle||Positive at 90° and negative at 270°|
|Consecutive test strikes||5 for each coupling mode and polarity/phase angle combination|
|Time between strikes||1 minute maximum between consecutive strikes|
|Total number of strikes for DUTs specified for use at a single input voltage||5 strikes x 4 coupling modes x 2 polarity/phase angles (40 total strikes)|
|Total number of strikes for DUTs specified for use over a range of input voltages||5 strikes x 4 coupling modes x 1 polarity/phase angle (positive at 90°) @ minimum specified input voltage, followed by 5 strikes x 4 coupling modes x 1 polarity/phase angle (negative at 270°) @ maximum specified input voltage (40 total strikes)|